炭化条件对猪粪水热炭主要营养成分的影响

Carbonization with main nutrients in pig manure hydrochar

以猪粪为原料,采用水热炭化法将猪粪转化为水热炭。考察了炭化温度(160,180,200,220和240℃),炭化时间(1,5,8 h)和原料含水率(70%,75%,80%)等条件对水热炭中主要营养成分及其回收率的影响。结果表明:猪粪水热炭中营养成分质量分数较高,其中有机碳质量分数为232.0~328.0 g·kg^(-1),总氮为25.2~31.8 g·kg^(-1),磷全量为21.5~30.6 g·kg^(-1),钾全量为3.4~12.5 g·kg^(-1)。当炭化温度从160℃升到240℃,水热炭中氮和有机碳回收率均降低,其中氮从66.29%降到41.95%,有机碳从49.61%降到29.07%。钾质量分数降低最大,为7.5 g·kg^(-1);磷质量分数升高了7.7 g·kg^(-1),但磷回收率几乎不变。炭化时间和原料含水率对水热炭的主要营养成分质量分数的影响较小,影响趋势与炭化温度相似。因此,炭化温度是影响水热炭成分质量分数的主要因素。

This study used hydrothermal carbonization technology to convert pig manure into hydrochar. The effect of carbonization temperature （160, 180, 200, 220, and 240 ℃）, carbonization time （1, 5, and 8 h）, and moisture content of pig manure （70%, 75%, and 80%） on major nutrients, and the recovery rate of hydroehar were determined. Results showed that the nutrient content in hydroehar was rich; the organic carbon （OC） ranged from 232.0-328.0 g·kg^-1, total nitrogen （TN） ranged from 25.2-31.8 g·kg^-1, phosphorus （P） ranged from 21.5-30.6 g·kg^-1, and potassium （K）ranged from 3.4-12.5 g·kg^-1 When the carbonization temperature from 160 ℃ to 240 ℃, the content and recovery rates of N and OC in hydroehar from 66.29% to 41.95% and 49.61% to 29.07%, respectively; with the decrease in K being 7.5 g·kg^-1; whereas, the content of P increased 7.7 g· kg^-1 with the recovery rate remaining almost unchanged. Because carbonization time and moisture content of the raw material were similar to that of carbonization temperature and because they had little effect; carbonization temperature was the main factor affecting the content of nutrient components in pig manure.